This invention relates to spatial filtering of laser ghosts.
In a servo writer that is used to write optical servo marks on a digital linear tape, ghost images are produced as a result of the non-ideal phase nature of a beam-generating device or due to the unwanted scattering in the optical system. The ghost images generate unwanted servo marks on the digital linear tape. The unwanted servo marks produced by the ghost images can degrade the tracking resolution and tracking accuracy. In severe cases, it renders optical tracking impossible.